Add job application quick reference for storing profile links and experience

Auth-protected CRUD for personal info (LinkedIn, GitHub, etc.) and
experience entries, stored in the database so nothing sensitive is in
the public repo. Displayed as a categorized panel on the Job Applications page.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/gqlgen.yml

@@ -69,3 +69,9 @@ models:
     fields:
       deletedAt:
         resolver: false
+  JobAppReference:
+    model:
+      - adam-french.co.uk/backend/models.JobAppReference
+    fields:
+      deletedAt:
+        resolver: false